Semi-active Vibration Control System Research Articles

Development of integrated semi-active adaptive vibration control system for bridges subjected to traffic loads

Nowadays, the fluid viscous damper is the most conventional energy dissipation system implemented in bridge structures to control the vibrations due to traffic loads. However, to effectively protect the bridge against frequent and severer vibrations, it is required to adapt the function of the damper according to the variable traffic loads. In this research, an Integrated Semi-Active Adaptive Vibration Control System is developed for the bridge structures. This control system consists of a Semi-Active Bypass Fluid Damper (SABFD), a programmable logic controller (PLC), pressure transducers, and displacement sensors. Semi-Active Bypass Fluid Damper is a hydraulic cylinder with a pair of external bypass pipes with motorized electric flow control valves which are installed in the middle of pipes to control the flow rate of the fluid. A programmable logic controller (PLC) is implemented to manage the operation of motorized valves according to the movement of the bridge.Therefore, the integrated control system is able to function as a real-time controller during its operation. To develop the control system, the performance of the SABFD device has been assessed through analytical model of the various control valve positions. Then, according to the structure response, a fuzzy control algorithm has been adapted in the PLC controller.Afterward, the prototypes of the SABFD and the PLC controller have been fabricated and a series of cyclic load tests have been conducted by using a dynamic actuator. The outcomes of the numerical analysis and results of the experimental tests revealed that the developed device is capable of generating a wide range of forces during device operation. The developed fuzzy control algorithm is then implemented to the finite element model of the bridge equipped with SABFD, and the results proved that the real-time control system effectively limits the bridge displacements according to the pre-defined fuzzy control rules.

Intelligent Control Methodology for Smart Highway Bridge Structures Using Optimal Replicator Dynamic Controller

Control algorithms are an essential part of effective semi-active vibration control systems used for the protection of large structures under dynamic loading. Adaptive control algorithms, which are data-driven methods, have recently been developed to replace model-based control algorithms, thus improving efficiency. The dynamic parameters of semi-actively controlled infrastructures will change after significant vibration loading. As a result, these structures require real-time, effective control actions in response to changing conditions, which classical controllers are unable to provide. To improve the efficiency of the semi-active controller, the optimal control algorithm was developed in this study. The algorithm is the integration of the replicator dynamics with an improved non-dominated sorting genetic algorithm (NSGA), which is NSGA-II. The optimal parameters of replicator dynamics (total resources, growth rate, and fitness function), which represent the behavior of the actuators, were obtained through a multi-objective optimization process. The new control system was then used to reduce the vibrations of the isolated highway bridge, which is equipped with semi-active control devices known as MR dampers. Moreover, the current study improved the performance of the structural control system with minimum energy consumption by assigning a specific growth rate to each control device. In order to reduce the vibrations of the highway bridge, the results show that the performance of the optimal replicator controller is better than the performance of the classical control algorithms. Doi: 10.28991/CEJ-2023-09-01-01 Full Text: PDF

A quasi-active negative stiffness damper for structural vibration control under earthquakes

This paper proposes a novel quasi-active negative stiffness damper (QANSD) for effective and robust seismic protection. By integrating the negative stiffness element and controllable damping element together, the proposed device enables to closely achieve active control performance with much less energy to operate compared to an active control system. Such a control system has been named as “Quasi-Active” control (QAC) in this study. To introduce the concept of QAC, this paper reiterates the fundamentals of active and semi-active vibration control systems from the perspective of control force, and numerically examines a few examples via comprehensive evaluation indices. The inherent shortfall of semi-active methods on control effectiveness is illustrated by an example of semi-active dampers. It is clearly revealed that the incapacity of semi-active control to capture the entire required active control force (RACF) is due to the fact that the amount of control force that can be generated by a semi-active control system is based on the responses of the structure, which prevents the semi-active control to achieve equivalent active control performance. To address this issue, this paper introduces the QAC concept and a specific realization, i.e. QANSD, including its principles, control strategy and realization. Furthermore, a generalized design approach and related formulae for designing the QANSD are developed with a special interest in obtaining its negative stiffness thresholds. Moreover, to demonstrate its control effectiveness and superiorities, comparative numerical studies are conducted based on a three-storey frame model. The comparisons are made among the same structure without control, with active control, semi-active control, passive control, as well as QAC. In the study, four scaled earthquakes are used as ground motion excitations and five evaluation criteria are adopted to assess the control performances. The results show that, with much less required energy, the QANSD is capable of completely producing RACF and its performance highly matches with the active control performance. Both of them can achieve similar inter-storey drift and displacement suppression effects as semi-active control, but much more evident acceleration and structural shear mitigation performance.

Semi-active vibration control of structural systems with a variable inerter

We propose a design method of semi-active vibration control systems using a variable inerter for structural systems subject to seismic disturbances. The inerter is a vibration control device generating resistance force proportional to the relative acceleration between both ends. In the variable inerter, the inertia mass of the inerter can be changed by a command signal in realtime. The mathematical model of the variable inerter is defined considering the dynamic delay of the inertia mass change subject to the command signal. For the dynamic model of a structural system with the variable inerter, we propose a semi-active control law based on a reference active control system. The reference active control system is a virtual system showing the ideal control performance. In the proposed semi-active control law, the variable inertia mass is changed by considering a predicted control output, the predicted error between the control output of the semi-active and reference active control systems, and the predicted reaction force of the inerter. The characteristic of the reference active control is optimized so that the control performance of the resulting semi-active control system is close to that of the best control systems among the passive off (without control), passive on (maximum inertia mass), and reference active control systems. A simulation study shows the effectiveness of the proposed semi-active control method.

Semi-Active Vibration Control Based on a Smart Exciter with an Optimized Electrical Shunt Circuit

A smart exciter coupled to cabin panels can be used as a new type of loudspeaker for emergency announcements in the aircraft cabin. The same device can also be used as a semi-active vibration control system which is effective in reducing the amplitude of structural vibration. The objective of this paper is to investigate the potential of vibration reduction using a smart exciter in combination with an optimized resistive-inductive shunt circuit, which serves as an absorbing network. First, the vibration reduction effect has been analyzed numerically using a simulation framework realized with COMSOL and MATLAB/Simulink. In a second step, the reduction effect of the smart exciter together with a resistive-inductive shunt circuit, which is produced by the Center of Applied Aeronautical Research (Zentrum für Angewandte Luftfahrtforschung GmbH, Hamburg, Germany), has been investigated experimentally. The results presented here prove that the smart exciter together with a resistive-inductive shunt can be highly effective in reducing structural vibrations.

Numerical and Experimental Investigation of a Semi-Active Vibration Control System by Means of Vibration Energy Conversion

A vibration control concept based on vibration energy conversion and storage with respect to a serial-stiffness-switch system (4S) has previously been proposed. Here, we first present a rotational electromagnetic serial-stiffness-switch system as a novel practical vibration control system for experimental validation of the concept and, furthermore, an improved control strategy for higher vibration suppression performance is also proposed. The system consists of two spring-switch elements in series, where a parallel switch can block a spring. As an alternating mechanical switch, the experimental system uses two electromagnets with a shared armature. By connecting the armature to the rotating load or the base, the electromagnets decide which of the two spiral springs is blocked, while the other is active. A switching law based on the rotation velocity of the payload is used. Modelling and building of the experimental system were carried out. The corresponding experiment and simulation were executed and they matched well. These results prove that our serial-stiffness-switch system is capable of converting vibration energy and realizing vibration reduction under a forced harmonic disturbance. The effects of disturbance frequency, disturbance amplitude and sampling frequency on the system performance are shown as well. A position feedback control-based switching law is further put forward and experimentally verified to improve the repositioning accuracy of the disturbed system.

Semi-active vibration control based on switchable transfer of bending moments: study and experimental validation of control performance

This paper presents an experimental approach to assessment of semi-active vibration control systems based on the Prestress–Accumulation Release concept. The objectives are threefold: (1) to introduce an experimental validation method for control algorithms based on switchable transfer of moments, (2) to propose a method to assess experimentally the control effects on structural dynamic response under several types of excitation, and (3) to propose an approach for adequate sensor placement. A laboratory frame demonstrator equipped with dedicated semi-active nodes is used. The proposed approach is based on spectral responses and modal analysis. According to the presented findings, the investigated control is effective in reducing the vibration level while keeping the structural dynamic stiffness at a proper level. The investigation is conducted in the case of free response, as well as responses to impact loading and random excitation. The results confirm the accuracy of the adopted algorithm parameters and reveal the sensor locations that provide the best control effectiveness.

Review on Development of High-Static–Low-Dynamic-Stiffness Seat Cushion Mattress for Vibration Control of Seating Suspension System

This review focuses on studying passive vibration isolation techniques and their applications. Advantages and disadvantages of different vibration isolation techniques will be compared in order to find an innovative method to reduce seating suspension system vibration and improve the ride comfort of vehicles’ drivers. Quasi-zero stiffness (QZS) isolators of high-static–low-dynamic stiffness are found to have good application prospects in low-frequency vibration isolation. In order to improve the isolation performance of the seating suspension system, a specially made seat cushion will be studied where a quasi-zero stiffness (QZS) isolator such as a double-diamond isolator is selected as one of the cells/units/elements of the seat cushion mattress. The double-diamond isolator structure does not represent the whole seating suspension system. The transmissibility ratio of the double-diamond isolator is evaluated by analytical and simulation models and compared to that of a conventional linear spring isolator. Although the performance of the passive vibration isolation/control system is usually worse than that of the active or semi-active control system, the cost of the passive vibration isolation/control system is lower than that of the active and semi-active control system, and the relative simplicity of adding a vibration isolation cushion mattress in an existing passive seating suspension system makes it low in cost, easy to implement, and more attractive than the active and semi-active vibration control systems.

Smart Semi-active PID-ACO control strategy for tower vibration reduction in Wind Turbines with MR damper

Wind turbine technology is well known around the globe as an eco-friendly and effective renewable power source. However, this technology often faces reliability problems due to structural vibration. This study proposes a smart semi-active vibration control system using Magnetorheological (MR) dampers where feedback controllers are optimized with nature-inspired algorithms. Proportional integral derivative (PID) and Proportional integral (PI) controllers are designed to achieve the optimal desired force and current input for MR the damper. PID control parameters are optimized using an Ant colony optimization (ACO) algorithm. The effectiveness of the ACO algorithm is validated by comparing its performance with Ziegler-Nichols (Z-N) and particle swarm optimization (PSO). The placement of the MR damper on the tower is also investigated to ensure structural balance and optimal desired force from the MR damper. The simulation results show that the proposed semi-active PID-ACO control strategy can significantly reduce vibration on the wind turbine tower under different frequencies (i.e., 67%, 73%, 79% and 34.4% at 2 Hz, 3 Hz, 4.6 Hz and 6 Hz, respectively) and amplitudes (i.e. 50%, 58% and 67% for 50 N, 80 N, and 100 N, respectively). In this study, the simulation model is validated with an experimental study in terms of natural frequency, mode shape and uncontrolled response at the 1st mode. The proposed PID-ACO control strategy and optimal MR damper position is also implemented on a lab-scaled wind turbine tower model. The results show that the vibration reduction rate is 66% and 73% in the experimental and simulation study, respectively, at the 1st mode.

Ability of Energy Harvesting Mr Damper to Act as a Velocity Sensor in Vibration Control Systems

Abstract The study investigates the self-sensing ability in an energy harvesting magnetorheological damper (EHMRD). The device consists of a conventional linear MR damper and an electromagnetic harvester. The objective of the work is to demonstrate that the EHMRD with specific self-powered feature can also serve as a velocity sensor. Main components of the device and design structure are summarized and its operation principle is highlighted. The diagram of the experimental set-up incorporating the measurement and processing unit is provided, the experimental procedure is outlined and data processing is discussed. The self-sensing function is proposed whereby the relative velocity of the EHMRD can be reconstructed from the electromotive force (emf) induced in the harvester coil. To demonstrate the adequacy of the self-sensing action (i.e., the induced emf should agree well with the relative velocity), the proposed self-sensing function is implemented and tested in the embedded system that will be a target control platform. Finally, the test results of the system utilizing a switching control algorithm are provided to demonstrate the potentials of the EHMRD acting as a velocity sensor and to confirm its applicability in semi-active vibration control systems.

Analysis of responses of semi-active vibration control systems using piezoelectric actuators to harmonic disturbance forces

Analysis of responses of semi-active vibration control systems using piezoelectric actuators to harmonic disturbance forces

An analysis of the effects of delay of sensor outputs on periodic responses of semi-active vibration control systems using piezoelectric actuators

An analysis of the effects of delay of sensor outputs on periodic responses of semi-active vibration control systems using piezoelectric actuators

Variable stiffness mechanisms of dual parameters changing magnetorheological fluid devices

Magnetorheological fluid (MRF) dampers are widely used as the variable damping devices in the semi-active vibration control system. In order to further improve the vibration reduction performance, a variable stiffness MRF damper with two chambers and two springs has been proposed recently. According to the test results, both of the damping and stiffness of the device can be controllable by changing the applied current independently. However, the mechanisms of variable stiffness for this device are still not clear. In this paper, the force transmissions of the parts of the variable stiffness MRF damper are analyzed, which reveals the variable stiffness mechanisms of dual parameters changing MRF devices. There are three stages for the variable stiffness MRF damper due to the friction and the yield of MR fluid. These stages can be controlled by the applied current of the different chambers, which changes the equivalent stiffness of the device. The proposed modelling of the device is verified by simulations and tests. In addition, the relationships between the equivalent stiffness and the parameters of the device are derived, which provide the design guidance for the variable stiffness MRF dampers.

Invited Review: Recent developments in vibration control of building and bridge structures

This paper presents a state-of-the-art review of recent articles published on active, passive, semi-active and hybrid vibration control systems for structures under dynamic loadings primarily since 2013. Active control systems include active mass dampers, active tuned mass dampers, distributed mass dampers, and active tendon control. Passive systems include tuned mass dampers (TMD), particle TMD, tuned liquid particle damper, tuned liquid column damper (TLCD), eddy-current TMD, tuned mass generator, tuned-inerter dampers, magnetic negative stiffness device, resetting passive stiffness damper, re-entering shape memory alloy damper, viscous wall dampers, viscoelastic dampers, and friction dampers. Semi-active systems include tuned liquid damper with floating roof, resettable variable stiffness TMD, variable friction dampers, semi-active TMD, magnetorheological dampers, leverage-type stiffness controllable mass damper, semi-active friction tendon. Hybrid systems include shape memory alloys-liquid column damper, shape memory alloy-based damper, and TMD-high damping rubber.

Periodic analysis of semi-active vibration control systems using piezoelectric actuators by shooting method

Periodic analysis of semi-active vibration control systems using piezoelectric actuators by shooting method

Investigation of an energy harvesting MR damper in a vibration control system

In this paper the authors investigate the performance of an energy harvesting MR damper (EH-MRD) employed in a semi-active vibration control system (SVCS) and used in a single DOF mechanical structure configuration. Main components of the newly proposed SCVS include the MR damper and an electromagnetic vibration energy harvester based on the Faraday’s law (EVEH) that converts vibration energy into electrical energy and delivers electrical power supplying the MR damper. The main objective of the study is to indicate that the SVCS, controlled by the specially designed embedded system, is feasible and presents good performance at the present stage of the research. The work describes investigation the unique features of the EH-MRD, i.e. its self-powering and self-sensing capabilities. Two cases were considered and the testing was done accordingly. In the case 1, only the self-powered capability was investigated. It was found out that harvested energy is sufficient to power the EH-MRD damper and to adjust it to structural vibration. The results confirmed the adequacy of the SVCS and demonstrated a significant reduction of the resonance peak. In the case 2, both the self-powering and self-sensing capabilities were investigated. Due to the self-sensing capability, the SCVS does not require any sensor. It appeared that thus harvested energy is sufficient to power the EH-MRD and enables self-sensing action since the signal of voltage induced by EVEH agrees with the relative velocity signal across the device. Similar to case 1, the resonance peak is significantly reduced.

Maximizing semi-active vibration isolation utilizing a magnetorheological damper with an inner bypass configuration

A single-degree-of-freedom (SDOF) semi-active vibration control system based on a magnetorheological (MR) damper with an inner bypass is investigated in this paper. The MR damper employing a pair of concentric tubes, between which the key structure, i.e., the inner bypass, is formed and MR fluids are energized, is designed to provide large dynamic range (i.e., ratio of field-on damping force to field-off damping force) and damping force range. The damping force performance of the MR damper is modeled using phenomenological model and verified by the experimental tests. In order to assess its feasibility and capability in vibration control systems, the mathematical model of a SDOF semi-active vibration control system based on the MR damper and skyhook control strategy is established. Using an MTS 244 hydraulic vibration exciter system and a dSPACE DS1103 real-time simulation system, experimental study for the SDOF semi-active vibration control system is also conducted. Simulation results are compared to experimental measurements.

Implementation of a Controllable Damper for Suppressing Vibration in the Technological Process

The paper deals with the problem of suppressing vibration of the arm of Motoman SSF200 robot within the frame of the technological process. Based on an overview of literature, a semi-active vibration control system was selected and a double ended magnetorheological damper (MR) was designed. After testing the acceleration of the robot arm in milling operation without the MR damper, the device was employed and the acceleration of the robot arm in four operation modes was experimentally tested.The conducted research has proved that the double ended MR damper can be practically applied for suppressing the vibration of the robot arm. The higher power to the electromagnet of the MR damper is exposed, the better vibration suppression is. This means that by changing the strength of current, the technological process of the robot arm is under control. Thus, control over the technological process is simplified when the physical characteristics of the milled material, milled tool or operation vary.

エネルギー回生式セミアクティブ振動制御装置に対するSRS制約を導入した圧電アクチュエータ最適配置

Vibration suppression is one of the most important problems in the design and operation of space structures. Due to limited launch capabilities, such structures need to be extremely light-weight although some structures succumb to vibrations because of their low structural stiffness. Moreover, vibrational energy is hard to disperse in the vacuum of space, in contrast to ground environments. These problems can be overcome by vibration control schemes.Vibration control schemes can be categorized into three types: active, passive and semi-active. The semi-active vibration control (SAVC), dynamically changes some property of the structure according to feedback from the state, without adding extra energy. SAVC systems are usually able to achieve higher performance than the passive vibration control schemes without the disadvantages of the active vibration control systems. In this study, optimal piezo actuator layout is solved by the introduction of Shock Response Spectrum (SRS) constraint which evaluates vibration and a shock.

B305 磁気粘性グリースを用いたせん断型セミアクティブダンパによる構造物の制振(OS14 制御用センサ・アクチュエータ)

This paper describes a successful application of Magnetorheological (MR) grease to a shear type controllable damper. MR fluid is known as a kind of functional fluids which changes rheological property when an external magnetic field is applied. However, there is a problem with the sedimentation of the dispersed particles. To prevent the sedimentation, MR grease was developed. In this study, we developed a shear type controllable damper using MR grease. The performance test demonstrated that the proposed damper has wide dynamic range of damping force despite its simple structure. The ratio of maximum damping force in on-state to that in off-state is approximately 65. In addition, the proposed damper was installed between first floor and second floor of a one-story model structure. The vibration control test demonstrated that the vibration response was successfully reduced by using the simplified skyhook algorithm. Our results indicate that the MR grease damper effectively works for the semi-active vibration control system.